feat: add callback accessors into operation class

[julshotal]

🧰 Changes

Adds support for RM-2271

The nested loops and array concatenation in this are super gross - they exist mostly due to callbacks being able to have multiple expressions and each expression being aPath Item Object which supports multiple methods and needing to concat these returned arrays to prevent nested arrays (we want just one array of multiple objects)

The operation class now has the following support for callbacks:

• hasCallbacks() returns a boolean based on whether or not the schema has any callbacks
• getCallback(identifier, expression, method) returns an operation created from a specific callback (found via the identifier, expression, and method)
• getCallbacks() returns an array of operations created via getCallback() for all existing callbacks
• getCallbackExamples() returns an object of the identifier, expression, method, and example (which and array of objects containing status and mediaTypes from getRequestExamples()) An array is used here instead of just an object in case the response for the example contains multiple status codes

🧬 QA & Testing

see tests*
callbacks.json is just the /callbacks route of kitchen-sink right now with an example added + callbacks with multiple expressions and methods for testing

*most of the testing for get-callback-examples is covered by the tests for get-response-examples due to the use of getResponseExamples(), but a few tests were duplicated for callbacks just to double check all info is coming back as intended!

[Dashron]

Tests look fine, what is getCallbackExamples used for? I don't remember a UI element that iterates over the callback examples but I could be misremembering.

[julshotal]

Tests look fine, what is getCallbackExamples used for? I don't remember a UI element that iterates over the callback examples but I could be misremembering.

The callback examples are going to be used to show a callback tab in the response component - this is the ticket that references it

[erunion]

Want to make this return a Callback instance? You can copy these couple lines from my webhook PR:

• https://github.com/readmeio/oas/pull/516/files#diff-f952ef6706aee84d0da82da3a6391a50394558b80d0ac7e4d437bcac22bb51aaR384-R387
• https://github.com/readmeio/oas/pull/516/files#diff-bfe9874d239014961b1ae4e89875a6155667db834a410aaaa2ebe3cf89820556R634

Should also update your tests to assert that this returns instances of that too.

[julshotal]

Had to disable an eslint rule but it should use a fresh Callback class now 👌

[erunion]

yeah it's ok to disable that multiple-class-per-file rule because it's not worth the trouble of having a 2 line file just to export a child class

[Dashron]

That link cleared up callback examples for me. Thanks! 👍 after Jon's comment is addressed!